Infinitely variable transmissions, continuously variable transmissions, methods, assemblies, subassemblies, and components therefor

ABSTRACT

Inventive embodiments are directed to components, subassemblies, systems, and/or methods for continuously and infinitely variable transmissions (IVT). In one embodiment, a variator is adapted to receive a control system that cooperates with a shift nut to actuate a ratio change in an IVT. In another embodiment, a neutral lock-out mechanism is adapted to cooperate with the variator to, among other things, disengage an output shaft from a variator. Various inventive mechanical couplings, such as an output engagement mechanism, are provided to facilitate a change in the ratio of an IVT for maintaining a powered zero operating condition. In one embodiment, the output engagement mechanism selectively couples an output member of the variator to a ratio adjuster of the variator. Embodiments of a ratio adjuster cooperate with other components of the IVT to support operation and/or functionality of the IVT. Among other things, user control interfaces for an IVT are disclosed.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. application Ser. No.14/338,661, filed Jul. 23, 2014 and scheduled to issue as U.S. Pat. No.9,683,640 on Jun. 20, 2017, which is a continuation of U.S. applicationSer. No. 14/024,955, filed Sep. 12, 2013 and issued as U.S. Pat. No.8,790,214 on Jul. 29, 2014, which is a continuation of U.S. applicationSer. No. 12/995,087, filed Nov. 29, 2010 and issued as U.S. Pat. No.8,535,199 on Sep. 17, 2013, which is a national phase application ofInternational Application No. PCT/US2008/066182, filed Jun. 6, 2008. Thedisclosures of all of the above-referenced prior applications,publications, and patents are considered part of the disclosure of thisapplication, and are incorporated by reference herein in their entirety.

BACKGROUND OF THE INVENTION Field of the Invention

The field of the invention relates generally to transmissions, and moreparticularly the inventive embodiments related to continuously variabletransmissions (CVTs) and infinitely variable transmissions (IVTs).

Description of the Related Art

In certain systems, power is characterized by torque and rotationalspeed. More specifically, power in these systems is generally defined asthe product of torque and rotational speed. Typically, a transmissioncouples to a power input that provides an input torque at an inputspeed. The transmission also couples to a load that demands an outputtorque and output speed, which may differ from the input torque and theinput speed. Typically, and generalizing, a prime mover provides thepower input to the transmission, and a driven device or load receivesthe power output from the transmission. A primary function of thetransmission is to modulate the power input in such a way to deliver apower output to the driven device at a desired ratio of input speed tooutput speed (“speed ratio”).

Some mechanical drives include transmissions of the type known asstepped, discrete, or fixed ratio. These transmissions are configured toprovide speed ratios that are discrete or stepped in a given speed ratiorange. For example, such a transmission may provide for a speed ratio of1:2, 1:1, or 2:1, but such a transmission cannot deliver intermediatespeed ratios such as 1:1.5, 1:1.75, 1.5:1, or 1.75:1, for example. Otherdrives include a type of transmission generally known as a continuouslyvariable transmission (or “CVT”), which includes a continuously variablevariator. A CVT, in contrast to a stepped transmission, is configured toprovide every fractional ratio in a given speed ratio range. Forexample, in the speed ratio range mentioned above, a CVT is generallycapable of delivering any desired speed ratio between 1:2 and 2:1, whichwould include speed ratios such as 1:1.9, 1:1.1, 1.3:1, 1.7:1, etc. Yetother drives employ an infinitely variable transmission (or “IVT”). AnIVT, like a CVT, is capable of producing every speed ratio in a givenratio range. However, in contrast to a CVT, the IVT is configured todeliver a zero output speed (a “powered zero” state) with a steady inputspeed. Hence, given the definition of speed ratio as the ratio of inputspeed to output speed, the IVT is capable of delivering an infinite setof speed ratios, and consequently, the IVT is not limited to a givenratio range. It should be noted that some transmissions use acontinuously variable variator coupled to other gearing and/or clutchesin a split powered arrangement to produce IVT functionality. However, asused here, the term IVT is primarily understood as comprehending aninfinitely variable variator which produces IVT functionality withoutbeing necessarily coupled to additional gearing and/or clutches.

The field of mechanical power transmission is cognizant of continuous orinfinitely variable variators of several types. For example, one wellknown class of continuous variators is thebelt-and-variable-radius-pulley variator. Other known variators includehydrostatic, toroidal, and cone-and-ring variators. In some cases, thesevariators couple to other gearing to provide IVT functionality. Somehydromechanical variators can provide infinite ratio variability withoutadditional gearing. Some variators, continuously and/or infinitelyvariable, are classified as frictional or traction variators becausethey rely on dry friction or elastohydrodynamic traction, respectively,to transfer torque across the variator. One example of a tractionvariator is a ball variator in which spherical elements are clampedbetween torque transfer elements and a thin layer of elastohydrodynamicfluid serves as the torque transfer conduit between the spherical andthe torque transfer elements. It is to this latter class of variatorsthat the inventive embodiments disclosed here are most related.

There is a continuing need in the CVT/IVT industry for transmission andvariator improvements in increasing efficiency and packagingflexibility, simplifying operation, and reducing cost, size, andcomplexity, among other things. The inventive embodiments of the CVTand/or IVT methods, systems, subassemblies, components, etc., disclosedbelow address some or all of the aspects of this need.

SUMMARY OF THE INVENTION

The systems and methods herein described have several features, nosingle one of which is solely responsible for its desirable attributes.Without limiting the scope as expressed by the claims that follow, itsmore prominent features will now be discussed briefly. After consideringthis discussion, and particularly after reading the section entitled“Detailed Description of Certain Inventive Embodiments” one willunderstand how the features of the system and methods provide severaladvantages over traditional systems and methods.

One aspect of the invention relates to a ball planetary infinitelyvariable transmission (IVT) having a shift rod driver and an outputfeedback rod. The output feedback rod is coupled to the shift roddriver. In one embodiment, the IVT includes a set of engagement pinsthat are configured to selectively couple to the output feedback rod.

Another aspect of the invention concerns a ball planetary infinitelyvariable transmission (IVT) having a throw-out bearing housing that iscoupled to an output member of the IVT. The IVT can include a neutralfork arm that has a first end and a second end. The first end of theneutral fork arm is coupled to the throw-out bearing housing. In oneembodiment, the IVT has a clevis member coupled to the second end of theneutral fork arm. The IVT can also include a knob coupled to the clevismember. The knob can be configured to be accessible from the exterior ofthe IVT.

Yet another aspect of the invention involves a variator for aninfinitely variable transmission (IVT). The variator can include a groupof power roller assemblies that are arranged angularly about alongitudinal axis of the transmission. The power roller assemblies areconfigured to tilt in operation. The variator can have a first tractionring in contact with the power rollers. The first traction ring issubstantially non-rotatable. In one embodiment, the variator has asecond traction ring in contact with the power rollers. The variator canalso include a carrier that is adapted to transfer an input power to thepower roller assemblies. In one embodiment, the variator has an outputmember operably coupled to the second traction ring. The output memberis adapted to translate along the longitudinal axis. The output memberis also configured to engage and disengage selectively from the secondtraction ring.

One aspect of the invention concerns a transmission having a group ofpower roller assemblies. The power roller assemblies are arrangedangularly about a longitudinal axis of the transmission. The powerroller assemblies are configured to tilt during operation. In oneembodiment, the transmission can have a first traction ring in contactwith the power rollers. The transmission can include a second tractionring in contact with the power rollers. In one embodiment, thetransmission has an idler in contact with the power rollers. The idleris adapted to translate with respect to the longitudinal axis. Thetransmission also has a shift rod sleeve operably coupled to the idler.The shift rod sleeve is configured to rotate with the idler. In someembodiments, the transmission has a shift rod driver arranged along thelongitudinal axis. The shift rod driver is operably coupled to the shiftrod sleeve. The transmission can include an output feedback rod coupledto the shift rod driver. The transmission can also include an outputengagement mechanism operably coupled to the output feedback rod. Theoutput engagement mechanism is configured to rotate with the secondtraction ring.

Another aspect of the invention relates to a neutral lock-out mechanismfor a transmission. The neutral lock-out mechanism has a throw-outbearing housing operably coupled to an output member of thetransmission. In one embodiment, the neutral lock-out mechanism has aneutral fork arm having a first end and a second end. The first end iscoupled to the throw-out bearing housing. The neutral lock-out mechanismcan have a clevis member coupled to the second end. The neutral lock-outmechanism can also have a knob coupled to the clevis member. The knobcan be configured to be accessible from the exterior of thetransmission.

Yet one more aspect of the invention addresses an output shaft assemblyfor a transmission. The output shaft assembly has an output shaft thathas a flange end and a splined end. The output shaft adapted totranslate axially. In one embodiment, the output shaft has a throw-outbearing housing operably coupled to the output shaft. In someembodiments, an axial translation of the throw-out bearing correspondsto an axial translation of the output shaft.

In another aspect, the invention concerns a control system for aninfinitely variable transmission (IVT). The control system has a shiftrod driver and an output feedback rod coupled to the shift rod driver.In one embodiment, the control system has a control interface housingoperably coupled to the shift rod driver. The control interface housingis configured to translate axially. The control system can also have anoutput member configured to be selectively coupled to the outputfeedback rod.

Another aspect of the invention relates to a method of controlling aninfinitely variable transmission (IVT). In one embodiment, the methodincludes providing a ratio adjuster coupled to the WT. The ratioadjuster is configured to actuate a change in transmission ratio of theIVT. The ratio adjuster has a shift rod driver and an output feedbackrod coupled to the shift rod driver. The ratio adjuster also has a shiftrod sleeve operably coupled to the output feedback rod. In oneembodiment, the method includes sensing a position of the ratio adjusterof the IVT. The position corresponds to a desired transmission outputspeed of zero. The method can include coupling operably an output memberof the IVT to the ratio adjuster. The method can also include actuatingthe ratio adjuster to maintain a zero output speed of the IVT.

One aspect of the invention relates to a method of controlling aninfinitely variable transmission (IVT) having a ratio adjuster and aball planetary variator. The method includes commanding an IVT outputspeed of zero. In one embodiment, the method includes sensing the IVToutput speed via a mechanical coupling. The mechanical coupling can beconfigured to couple to both the ratio adjuster and the variator. Themethod can also include adjusting the mechanical coupling to maintainthe IVT output speed at zero.

Another aspect of the invention addresses a ratio adjuster for aninfinitely variable transmission (IVT) having a variator. The ratioadjuster has a shift rod driver and an output feedback rod coupled tothe shift rod driver. In one embodiment, the ratio adjuster has a shiftrod sleeve operably coupled to the output feedback rod. The shift rodsleeve is arranged radially outward of, and coaxially with, the outputfeedback rod. The shift rod sleeve is coupled to the variator.

One more aspect of the invention concerns a control interface apparatusfor a control system having a shift rod driver and a user interface. Thecontrol interface apparatus includes a housing having a central bore andan adjustment member coupled to the central bore. In one embodiment, thecontrol interface apparatus includes a first threaded portion located onthe central bore. The first threaded portion adapted to receive athreaded portion of the shift rod driver. The control interfaceapparatus also includes a second threaded portion on the central bore.The second threaded portion is adapted to receive the adjustment member.

Yet another aspect of the invention involves an output engagementmechanism for an infinitely variable transmission (IVT). The outputengagement mechanism has a housing and an output member operably coupledto the IVT. The output member is operably coupled to the housing. Theoutput engagement mechanism can include an output feedback rodselectively coupled to the housing. The output feedback rod operablycouples to the housing at an output speed of the IVT substantially equalto zero. In one embodiment, the output engagement mechanism includes agroup of engagement pins operably coupled to the housing. The engagementpins are arranged angularly about, and extending radially from, alongitudinal axis of the output feedback rod. The output engagementmechanism also includes a groups of springs operably coupled to theengagement pins.

Another aspect of the invention relates to a housing assembly for anoutput engagement mechanism having a first generally cylindricalhousing. The first generally cylindrical housing has a first centralbore, a first end, and a second end. The housing assembly includes a setof flat surfaces formed on an exterior perimeter of the cylindricalhousing. The housing assembly also includes a first set of channelsformed on the first end. The channels extend radially outward from thecentral bore. In one embodiment, the housing assembly includes aretaining cap coupled to the first end of the cylindrical housing. Theretaining cap has a second set of channels configured to substantiallyalign with the first set of channels.

Yet one more aspect of the invention addresses a shift rod driver havinga substantially cylindrical rod having a first end and a second end. Theshift rod driver has a reaction flange configured on the first end and afirst threaded portion formed on the second end. The shift rod driveralso has a second threaded portion formed on the first end.

Another aspect of the invention relates to a shift rod member having asubstantially cylindrical body with a first end and a second end. Thefirst end has a threaded bore. The shift rod member has a set ofengagement surfaces formed on the outer periphery of the cylindricalbody. The engagement surfaces can be located in proximity to the secondend. The shift rod member also has a bearing flange formed on the outerperiphery of the cylindrical body. The bearing flange can be locatedbetween the threaded bore and the engagement surfaces.

Yet another aspect of the invention involves a shift rod sleeve for acontrol system of an infinitely variable transmission (IVT). The shiftrod sleeve has a substantially cylindrical body having a first centralbore and a second central bore. The first central bore is arranged on afirst end of the cylindrical body, and the second central bore isarranged on a second end of the cylindrical body. The first central borehas a different diameter than the second central bore. The shift rodsleeve also has an end cup extending from the second end of thecylindrical body. The end cup can be configured to couple to an outputengagement rod of the control system. The end cup has a cup threadedportion. The shift rod sleeve also has a reaction face formed on aninterior surface of the end cup.

In another aspect, the invention concerns a carrier nut for aninfinitely variable transmission (IVT). The carrier nut has asubstantially cylindrical body having a central bore formed with athreaded portion. The threaded portion configured to couple to a mainshaft of the IVT. The carrier nut has a first reaction surface formed ona face of one end of the cylindrical body. The carrier nut can have asecond reaction surface formed on the outer periphery of the cylindricalbody. The carrier nut can also have a shoulder configured on the outercircumference of the cylindrical body. The shoulder adapted to support abearing of the IVT.

Another aspect of the invention relates to a housing for a transmission.The housing can have an upper housing member with a flange surfacehaving a first group of fastening holes. The housing includes a firstset of cooling fins extending outwardly and inwardly from a main cavityof the upper housing member. In one embodiment, the housing includes apiloting shoulder adapted to align and support a control mechanism ofthe transmission. The housing also includes an intermediate platecoupled to the upper housing member. In one embodiment, the housingincludes a lower housing member having a flange surface with a secondgroup of fastening holes. The flange surface configured to couple to theintermediate plate. The lower housing member can also include a secondgroup of cooling fins extending outwardly and inwardly from a maincavity of the lower housing member. The lower housing member can alsoinclude a support hub located on the interior of the main cavity of thelower housing member. The support hub has a number of grooves andshoulders.

BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 is a perspective view of a transmission that uses an infinitelyvariable variator (IVT) in accordance with inventive embodimentsdisclosed herein.

FIG. 2 is a cross-sectional view of the transmission of FIG. 1.

FIG. 3 is a second cross-sectional view of the transmission of FIG. 1.

FIG. 4 is a partially exploded assembly view of the transmission of FIG.1.

FIG. 5 is a cross-sectional view of an IVT that can be used with thetransmission of FIG. 1.

FIG. 6 is an exploded assembly view of certain components of the IVT ofFIG. 5.

FIG. 7A is a perspective view of certain components a neutral lock-outdevice that can be used with the transmission of FIG. 1.

FIG. 7B is a perspective view of an exemplary manual neutral knob thatcan be used with the neutral lock-out device of FIG. 7A.

FIG. 7C is a perspective view of an exemplary switch cam that can beused with the neutral lock-out device of FIG. 7A.

FIG. 7D is a perspective view of an exemplary switch that can be usedwith the neutral lock-out device of FIG. 7A.

FIG. 8A is a perspective view of certain components of an output shaftassembly that can be used in the transmission of FIG. 1.

FIG. 8B is a cross-sectional view of the output shaft assembly of FIG.8A.

FIG. 9A is a perspective view of an output coupling that can be usedwith the IVT of FIG. 5.

FIG. 9B is a perspective view of the output coupling of FIG. 9A.

FIG. 9C is a cross-sectional view of the output coupling of FIG. 9A.

FIG. 10A is a cross-sectional view of certain components of a controlsystem that can be used with the IVT of FIG. 5.

FIG. 10B is a Detail A view of the control system of FIG. 10A.

FIG. 10C is a Detail B view of the control system of FIG. 10A.

FIG. 10D is a cross-sectional view of certain components of the controlsystem of FIG. 10A.

FIG. 11A is a perspective view of an exemplary control interfacemechanism housing that can be used with the control system of FIG. 10A.

FIG. 11B is a cross-sectional view of the control interface mechanismhousing of FIG. 11A.

FIG. 12A is an exploded assembly view of certain components of an outputengagement mechanism that can be used with the control system of FIG.10A.

FIG. 12B is a cross-sectional view of the components of the outputengagement mechanism of FIG. 12A.

FIG. 13A is a perspective view of an output engagement mechanism housingthat can be used with the output engagement mechanism of FIG. 12A.

FIG. 13B is a cross-sectional view of the output engagement mechanismhousing of FIG. 13A.

FIG. 13C is another perspective view of the output engagement mechanismhousing of FIG. 13A.

FIG. 13D is a perspective view of an output engagement mechanism capthat can be used with the output engagement mechanism of FIG. 12A.

FIG. 13E is a perspective view of an engagement pin that can be usedwith the output engagement mechanism of FIG. 12A.

FIG. 13F is a cross-sectional view of the engagement pin of FIG. 13E.

FIG. 14 is a perspective view of a shift rod driver that can be usedwith the control system of FIG. 10A.

FIG. 15A is a perspective view of an output feedback rod that can beused with the control system of FIG. 10A.

FIG. 15B is a cross-sectional view of the output feedback rod of FIG.15A.

FIG. 15C is a Detail C view of the shift rod member of FIG. 15A.

FIG. 15D is a cross-sectional view of another embodiment of the outputfeedback rod of FIG. 15A.

FIG. 16A is a perspective view of a shift rod sleeve that can be usedwith the control system of FIG. 10A.

FIG. 16B is a cross-sectional view of the shift rod sleeve of FIG. 16A.

FIG. 17A is a perspective view of a cap that can be used with thecontrol system of FIG. 10A.

FIG. 17B is a cross-sectional view of the cap of FIG. 17A.

FIG. 18 is a perspective view of a shift rod nut that can be used in thecontrol system of FIG. 10A.

FIG. 19A is a perspective view of a carrier nut that can be used withthe IVT of FIG. 5.

FIG. 19B is a cross-sectional view of the carrier nut of FIG. 19A.

FIG. 20A is a top elevational view of a main shaft that can be used withthe IVT of FIG. 5.

FIG. 20B is side elevational view of the main shaft of FIG. 20A.

FIG. 20C is a cross-sectional view of the main shaft of FIG. 20A.

FIG. 20D is a Detail D view of the main shaft of FIG. 20A.

FIG. 20E is a Detail E view of the main shaft of FIG. 20A.

FIG. 21 is an exploded assembly view of a housing that can be used withthe transmission of FIG. 1.

FIG. 22A is a perspective view of the lower housing member of thehousing assembly of FIG. 21.

FIG. 22B is a cross-sectional, perspective view of the lower housingmember of FIG. 22A.

FIG. 22C is a Detail F view of the lower housing member of FIG. 22B.

FIG. 23A is a perspective view of an upper housing member of the housingassembly of FIG. 21.

FIG. 23B is a cross-sectional, perspective view of the upper housingmember of FIG. 23A.

DETAILED DESCRIPTION OF CERTAIN INVENTIVE EMBODIMENTS

The preferred embodiments will now be described with reference to theaccompanying figures, wherein like numerals refer to like elementsthroughout. The terminology used in the description presented herein isnot intended to be interpreted in any limited or restrictive mannersimply because it is being utilized in conjunction with a detaileddescription of certain specific embodiments of the invention.Furthermore, embodiments of the invention may include several novelfeatures, no single one of which is solely responsible for its desirableattributes or which is essential to practicing the inventions hereindescribed. The CVT/IVT embodiments described here are generally relatedto transmissions and variators disclosed in U.S. Pat. Nos. 6,241,636,6,419,608, 6,689,012, 7,011,600, and U.S. patent application Ser. Nos.11/243,484 and 11/543,311. The entire disclosure of each of thesepatents and applications is hereby incorporated herein by reference.

As used here, the terms “operationally connected,” “operationallycoupled”, “operationally linked”, “operably connected”, “operablycoupled”, “operably linked,” and like terms, refer to a relationship(mechanical, linkage, coupling, etc.) between elements whereby operationof one element results in a corresponding, following, or simultaneousoperation or actuation of a second element. It is noted that in usingsaid terms to describe inventive embodiments, specific structures ormechanisms that link or couple the elements are typically described.However, unless otherwise specifically stated, when one of said terms isused, the term indicates that the actual linkage or coupling may take avariety of forms, which in certain instances will be obvious to a personof ordinary skill in the relevant technology.

For description purposes, the term “radial” is used here to indicate adirection or position that is perpendicular relative to a longitudinalaxis of a transmission or variator. The term “axial” as used here refersto a direction or position along an axis that is parallel to a main orlongitudinal axis of a transmission or variator. For clarity andconciseness, at times similar components labeled similarly (for example,control piston 582A and control piston 582B) will be referred tocollectively by a single label (for example, control pistons 582).

Referring to FIGS. 1-4, in one embodiment an infinitely variabletransmission (IVT) 100 includes a housing assembly 102 adapted tocooperate with a control assembly 104. The IVT 100 can be coupled to apower input with an input pulley 106, for example. Among other things,the housing assembly 102 encloses most of the components of the IVT 100and provides structural support for mounting the IVT 100 to, forinstance, a vehicle frame or other components in the drivetrain such asa gearbox, differential, or axle. In some embodiments, the IVT 100includes a manual neutral knob assembly 108 that can couple to certaincomponents that are inside the housing assembly 102. The manual neutralknob assembly 108 can provide an interface to allow manual disconnectionbetween the input pulley 106 and a driven device, such as a driven axleon a lawn tractor. In one embodiment, a number of cooling fins 110 areformed on the housing assembly 102. The cooling fins 110 can aid inthermal management of the IVT 100.

Turning now to FIG. 2 more specifically, in one embodiment of the IVT100 the housing assembly 102 encloses a variator 200 that can beoperably coupled to the input pulley 106 and to an output shaft 210. Insome embodiments, the housing assembly 102 supports a neutral fork arm220 which can couple to the manual neutral knob assembly 108. The manualneutral knob assembly 108 can be connected to a clevis member 222, forexample. A holding spring 224 can be coupled to the clevis member 222.In one embodiment, adjustment of the manual neutral knob assembly 108,typically by rotation to a predetermined angular position, translatesthe clevis member 222 and energizes the holding spring 224, wherebyadjustment of the manual neutral knob assembly 108 results in movementof the neutral fork arm 220 about a pivot 223. In some embodiments, theneutral fork arm 220 couples to a throw-out bearing housing 226, whichthrow-out bearing housing 226 is configured to engage and disengage theoutput shaft 210. An axial thrust bearing 211 and a needle rollerbearing 212 can be provided to support, among other things, certaincomponents of the variator 200.

In one embodiment, the IVT 100 includes a control interface mechanism230 to facilitate adjustment of the speed ratio of the IVT 100. In someembodiments, the control interface mechanism 230 can be coupled to aratio adjuster 240 that couples to certain components of the variator200. As shown in FIG. 3, in one embodiment the control interfacemechanism 230 can be coupled to a control linkage 310, which controllinkage 310 can be supported on the housing 102 at a pivot 312, andwhich control linkage 310 couples additionally, in one embodiment, to acoupling member 314. The coupling member 314 is preferably adapted tointeract with a user control interface such as a foot pedal or a handlever (not shown) for communicating adjustments in transmission ratiofrom a user (or, alternatively or additionally, an automated or asemi-automated command system) to the IVT 100. In one embodiment of thecontrol linkage 310, the coupling member 314 couples to a pivot 315arranged on one end of a pivot lever 316. An intermediate linkage 318couples to the pivot lever 316 at a pivot 317. Translation of thecoupling member 314 tends to rotate the pivot lever 316 around the pivot312 and, thereby, tends to translate the control linkage 318. In someembodiments, the control linkage 318 couples to a shift fork 320 at apivot 319. The shift fork 320 couples to the control interface mechanism230. The shift fork 320 can couple to a pivot 321, which in oneembodiment is supported by a ground member 330. The ground member 330can be attached to, for example, the vehicle chassis.

Turning now to FIG. 4, in one embodiment of the IVT 100, the housingassembly 102 can include an upper housing member 102A, an intermediateplate 102C, and a lower housing member 102B. The housing members 102A,102B, and 102C are coupled in a suitable manner, such as with bolts,screws, or clamps. The variator 200 can be positioned on the interior ofthe housing assembly 102 and towards one side thereby creating aninternal volume to provide, for instance, a reservoir for lubricant. Insome embodiments, a housing cap 410, a flange seal 412, and a shaft seal414 couple to the upper housing member 102A. The housing cap 410 canseal the IVT 100. The variator 200 can be provided with a number ofsprings, for example coil springs 202, which can couple the variator tothe upper housing member 102A. The coil springs 202 can facilitate theprovision of a preload on components of the variator 202.

Referring now to FIG. 5, in one embodiment a variator 200 is configuredto receive input power from a pulley 106 on a main shaft 510. The mainshaft 510 can be attached to a carrier 512 with a carrier clamp 514.Power is transferred to the carrier 512, which facilitates theinfinitely variable ratio range. IVT functionality allows delivery of azero output speed (a “powered zero” condition) with a non-zero inputspeed of a power delivery device. The carrier 512 provides support to anumber of power roller assemblies 502, among other things. The carrierclamp 514 is configured to receive a support bearing 515A. In someembodiments, the bearing 515A can operably couple the variator 200 andthe housing assembly 102. An exemplary power roller assembly 502 isdescribed in U.S. patent application Ser. No. 11/543,311, the entiredisclosure of which is hereby incorporated herein by reference. In oneembodiment, a traction ring 516 couples to a clamp force generatorassembly 518. The clamp force generator assembly 518 can include areaction member 520 and a number of load cam rollers 522. In someembodiments, the reaction member 520 couples to the upper housing member102A with, for example, dowel pins and coil springs 202. The variator200 can be configured to have an output traction ring 524 in contactwith the power roller assembly 502. The output traction ring 524 cancouple to a second axial force generator mechanism that includes anumber of load cam rollers 522 and to a reaction member 526. Thereaction member 526 can attach to an output member 528 with, forinstance, dowel pins, so that relative motion between the two members isprevented. In other embodiments, the coupling between the reactionmember 526 and the output member 528 can be a frictional coupling.

Referring now to FIG. 5 and FIG. 6, in one embodiment of the variator200, a ratio adjuster 240 can be arranged coaxially and radially inwardof the main shaft 510. The ratio adjuster 240 can couple to an idlerassembly 504. An adjustment of the ratio adjuster 240 tends to translateaxially the idler assembly 504, thereby adjusting the speed ratio of theIVT 100. In some embodiments, the ratio adjuster 240 can couple to anoutput engagement mechanism 530. Under certain operating conditions,such as powered zero, the output member 528 can be operably coupled tothe ratio adjuster 240. In one embodiment, the ratio adjuster 240 issupported radially along the central axis of the variator 200 bybearings 540 and 542, which can be coupled to the main shaft 510. Theratio adjuster 240 can be additionally supported by a bearing 544 thatis received and supported by the output member 528 in a bore 545.

Turning to FIG. 2 and FIG. 6, in one embodiment of the variator 200, theoutput shaft 210 is coupled to the output member 528 with, for example,a number of dowels 611. The dowels 611 can be arranged angularly about,and substantially coaxial with, the main axis of the IVT 100. The outputshaft 210 and the output member 528 can be rigidly linked duringoperation. The throw-out bearing housing 226 can be coupled to theoutput shaft 210 with, for instance, a radial ball bearing 227. Thethrow-out bearing housing 226 can be radially supported in the housingassembly 102 and constrained from rotation with at least two dowels 612.The dowels 612 can also couple to the neutral fork arm 220. The neutralfork arm 220 can be used to translate axially the throw-out bearinghousing 226 thereby selectively engaging and disengaging the outputshaft 210 from the output member 528.

Passing now to FIG. 7A, in one embodiment of the IVT 100, a neutral lockout mechanism 700 can be coupled to the variator 200. The neutral lockout mechanism 700 can include a throw-out bearing housing 226 coupled toone end of a neutral fork arm 220. The neutral fork arm 220 can besupported at a pivot 223 with a bracket 730. The clevis member 222 canbe connected to the neutral fork arm 220 at pivot 722. The neutral knobassembly 108 can include, in one embodiment, a knob 710 and a switch cam712. The neutral knob assembly 108 can couple to one end of the clevismember 222. In some embodiments, a spring 224 can cooperate with theclevis member 222. One end of the spring 224 couples to the clevismember 222 while the other end of the spring 224 couples to the housing102. In some embodiments, a kill switch 720 couples to the switch cam712 thereby allowing the activation of the neutral lock out mechanism700 to be communicated to, for example, the electrical system of avehicle. During operation of the IVT 100, the neutral lock out mechanism700 is inactive and therefore the neutral throw-out bearing housing 226is positioned to allow engagement of the output shaft 210 with theoutput member 528. During certain operating conditions, it is desirableto decouple the variator 200 from the output shaft 210. The neutral lockout mechanism 700 can be used for this purpose. The neutral knobassembly 108 can be adjusted to a predetermined position by pulling theknob 710 away from the housing 102 and rotating the knob 710 through anarc of, for example, about 90 degrees. This action translates the clevismember 222, compresses the spring 224 between the housing 102 and theclevis member 222, and pivots the neutral fork arm 220, thereby axiallytranslating the throw-out bearing housing 226.

Turning to FIG. 7B through FIG. 7D, in one embodiment the neutral knob710 can be a substantially cylindrical body formed with a central bore711. The central bore 711 can be adapted to receive one end of theclevis member 222. The neutral knob 710 can have a shoulder 713 thatextends from the main body. The shoulder 713 can be adapted to mate withthe switch cam 712. In one embodiment, the switch cam 712 includes amain bore 716 and a number of guide bores 717. The guide bores 717 canfacilitate the selective coupling of the switch cam 712 to a housingmember such as housing member 102A via a number of dowel pins (notshown). The body of the switch cam 712 can have a switch cam extension715 adapted to couple to the kill switch 720. In one embodiment, thekill switch 720 includes a switch button 721 supported in a housing 722.A number of fastener holes 723 can be provided in the housing 722 tofacilitate, for example, attaching the kill switch 720 to the chassis ofa vehicle.

Referring now to, FIGS. 8A and 8B, in one embodiment an output shaft 210is adapted to cooperate with the neutral throw-out bearing housing 226.A ball bearing 227 can be supported in the neutral throw-out bearinghousing 226. The ball bearing 227 can be supported by the output shaft210 on a bearing seat 818. A snap ring 811A can be inserted in a snapring groove 820; the snap ring 811A is suitably adapted to securebearing race 810. Likewise, a snap ring 811B can be provided to secure abearing race of the bearing 227 in the neutral throw-out bearing housing226. In one embodiment, the output shaft 210 has a splined end 824 and aflange end 816. The flange end 816 can include a number of holes 610adapted to receive, for example, the dowels 611. The output shaft 210can be provided with a seal surface 822 adapted to receive a shaft seal,for example. The end 816 can include a counter bore 812 to provideclearance for certain components of the ratio adjuster 240.

Turning to FIGS. 9A-9C, in one embodiment the output member 528 can be agenerally hollow cylindrical body with an output member end 911A and anoutput member end 911B. The output member end 911A is adapted to coupleto the axial force reaction member 526. The output member end 911B isadapted to couple to the output shaft 210. In some embodiments, a numberof dowel bores 910 are formed on the output member end 911A. The dowelbores 910 are adapted to constrain a number of dowels 611. The dowels611 can couple the output member 528 to the axial force reaction member526. In some implementations, a number of drain holes 912 can bearranged radially on the outer circumference of the output member 528.The drain holes 912 facilitate the drainage of lubricant from theinterior of the variator 200. Focusing now on the output member end911B, a shoulder 914 can be provided to mate with the axial thrustbearing 211 (see, for example, FIG. 2). In some embodiments, a flangesurface 916 is provided with bores 915 to receive a number of dowels611. The flange surface 916 can mate with the output shaft 210. Acylindrical shoulder 917 can extend from the flange surface 916 toprovide support for the needle roller bearing 212 (see, for example,FIG. 2). Among other things, the shoulder 914 and the shoulder 917support the variator 200 in the housing assembly 102. The inner bore ofthe output member 528 is substantially cylindrical and can have, forexample, a number of flat spring reaction surfaces 920 that can beconfigured to mate with an output engagement mechanism 530 (see, forexample, FIG. 5).

Referring to FIGS. 10A, 10B, 10C, and 10D now, a control system 1000that can be adapted to cooperate with the variator 200 will bedescribed. In one embodiment, the control system 1000 includes a controlinterface mechanism 230, a ratio adjuster 240, and an output engagementmechanism 530. In some embodiments, the ratio adjuster 240 includes ashift rod subassembly 1001 and a shaft subassembly 1002. In oneembodiment, the shift rod subassembly 1001 includes a shift rod driver1001A and an output feedback rod 1001B. The shift rod driver 1001A andthe output feedback rod 1001B can be coupled with threads 1003, forexample. Once assembled, the shift rod driver 1001A and the outputfeedback rod 1001B form a substantially rigid shift rod subassembly1001. The shaft subassembly 1002 can be arranged radially outward of andcoaxially with the shift rod subassembly 1001. In some embodiments, theshaft subassembly 1002 includes a shift rod sleeve 1002A coupled to acap 1002B. The shift rod sleeve 1002A can be configured to adapt to ashift nut 1006. The shift nut 1006 can be retained on or by the shiftrod sleeve 1002A with, for example, a snap ring 1007. The shift nut 1006can be further coupled to the idler assembly 504 (See, for example, FIG.5). The shaft subassembly 1002 is supported on the shift rod subassembly1001 with, for example, bearings 1004 and 1005. The bearings 1004 and1005 can be, for example, needle roller bearings and can be constrainedbetween the shift rod subassembly 1001 and the shaft subassembly 1002.

Referring now to FIGS. 10A, 11A and 11B, in one embodiment a controlinterface mechanism housing 1100 is a substantially cylindrical bodywith a central bore 1102 having two portions of different diameters. Oneportion of the central bore 1102 is threaded with, for example, astraight thread 1106. The threaded portion 1106 can be adapted toreceive adjustment members 1020 and 1021. The adjustment members 1020and 1021 constrain certain parts of the ratio adjuster 240 duringoperation. The central bore 1102 can include a second threaded portionhaving, for example, an acme thread 1108. The acme thread 1108 can beconfigured to mate with a threaded portion of the shift rod driver1001A. The control interface mechanism housing 1100 can include tappedholes 1104A and 1104B to connect to, for example, the shift fork 320with fasteners such as bolts or screws (not shown).

Turning now to FIGS. 12A and 12B, in one embodiment the outputengagement mechanism 530 can be a mechanical coupling configured tofacilitate a selective connection between, for example, the outputmember 528 and the ratio adjuster 240. In some embodiments, the outputengagement mechanism 530 rotates with, for example, the output member528. In one embodiment, the output engagement mechanism 530 includes agenerally cylindrical housing 1200 coupled to a retaining cap 1202. Theengagement mechanism housing 1200 and the retaining cap 1202 enclose anumber of springs 1008 and pins 1010. In the illustrated embodiment,four pins 1010 and four springs 1008 are arranged angularly about thecentral axis of the housing 1200. The output engagement mechanism 530 isconfigured to cooperate with the variator 200. In one embodiment, theoutput engagement mechanism 530 surrounds certain components of theratio adjuster 240. Under certain operating conditions, such as poweredzero, the output engagement mechanism 530 can couple to certaincomponents of the ratio adjuster 240, for example, the output feedbackrod 1001B. In some implementations, the output engagement mechanism 530turns the output feedback rod 1001B thereby shifting the variator 200.

Turning to FIGS. 13A-13F, in one embodiment the housing 1200 includes agenerally cylindrical body with a central bore 1302. One end of thehousing 1200 can include a shoulder 1310. The shoulder 1310 canfacilitate the radial and axial alignment of the bearing 515B (see FIG.5). In some embodiments, a number of flat surfaces 1312 can be arrangedon the outer circumference of the housing 1200. The flat surfaces 1312generally cooperate with the spring reaction surfaces 920 formed on theinner bore of output member 528 (see, for example, FIG. 9A). A number ofholes 1314 provide clearance for fasteners that secure the housing 1200to both the retaining cap 1202 and the output member 528 with, forexample, bolts. A number of counter bores 1316 can be formed in thehousing 1200 to provide clearance to, for example, bolt heads (notshown). The central bore 1302 is generally sized to provide clearancefor certain components of the ratio adjuster 240. The housing 1200 canadditionally include a number of channels 1318 and reaction surfaces1320 formed on the end of the housing 1200 that is opposite to the endof the housing 1200 having the shoulder 1310. The channels 1318 can bearranged to support the pins 1010. Similarly, the retaining cap 1202 isa generally cylindrical disk with a central bore 1303 that can provideclearance for certain components of the ratio adjuster 240. A number ofholes 1315 can be provided on the retaining cap 1202 and adapted tocooperate with the holes 1314. A number of channels 1319 are configuredon one face of the retaining cap 1202. The channels 1319 aresubstantially similar to the channels 1318 and are adapted to receivethe pins 1010. The retaining cap includes a number of reaction surfaces1321, which are adapted to mate with the pins 1010. The pins 1010 can begenerally hollow cylindrical bodies with an inner counter bore 1334. Thepins 1010 include a number of external reaction surfaces 1330 adapted tomate with, for instance, the reaction surfaces 1320 and 1321. Each innerbore 1334 is adapted to receive a spring 1008 (see, for example, FIG.12B). The springs 1008 are configured to press the pins 1010 against thereaction surfaces 1320 and 1321. The pins 1010 can couple to certaincomponents of the ratio adjuster 240 with an engagement shoulder 1332that extends from the reaction surface 1330 of the pin 1010. In oneembodiment, the reaction surfaces 1320 and 1321 are configured toprevent the engagement shoulder 1332 from contacting the ratio adjuster240 during certain operating conditions, namely conditions with non-zerooutput speed, for example.

Passing now to FIGS. 14-18, in one embodiment a shift rod driver 1001Aincludes a generally cylindrical rod 1410 formed with a reaction flange1412 on one end and a fastening thread 1003 on the other end. A screwlead 1414 can be an acme thread, for example, adapted to cooperate withthe acme thread 1108 provided in the control interface housing 1100(see, for example, FIG. 11A). The reaction flange 1412 can be configuredto cooperate with the control interface housing 1100 and the adjustmentmembers 1020 and 1021 (see, for example, FIG. 10A). The fastening thread1003 couples the shift rod driver 1001A to the output feedback rod1001B. In one embodiment, the output feedback rod 1001B can be asubstantially cylindrical body provided with a threaded bore 1510 on oneend, a bearing flange 1514, and a number of engagement surfaces 1512.The bearing flange 1514 includes reaction surfaces 1516 and 1518. Thereaction surfaces 1516 and 1518 are adapted to cooperate with, forexample, needle bearings 1004 and 1005, respectively. The engagementsurfaces 1512 can be adapted to cooperate with the output engagementmechanism 530 and the engagement shoulder 1332 on the pin 1010. A numberof profiled ramps 1520A and 1520B can be formed on the output feedbackrod 1001B. Preferably, the profiled ramps 1520 are adapted to guide andcapture the engagement shoulders 1332. In some embodiments, a number ofengagement surfaces 1530 can be formed on the output feedback rod 1001B.The engagement surfaces 1530 can be substantially similar in function tothe engagement surfaces 1512. A number of profiled ramps 1532A and 1532Bcan be arranged to cooperate with the engagement shoulders 1332 forguiding and capturing the pins 1010.

Turning to FIGS. 16A-17B, in one embodiment, the shift rod sleeve 1002Acan be a generally hollow cylindrical body having a first bore 1730 anda second bore 1732. The shift rod sleeve 1002A can be operationallycoupled to the variator 200, and more specifically to the idler assembly504. The two bores 1730 and 1732 are configured to provide clearance forthe shift rod driver 1001A and the output feedback rod 1001B. The shiftrod sleeve 1002A can be formed with a cup end 1702, which is adapted toenclose a number of needle bearings 1004 and 1005. The cup end 1702includes threads 1710 configured to mate with the threads 1610 of theretaining cap 1002B. The reaction face 1712 can support the bearing1004, for example. A reaction face 1620 can be provided on one end ofthe retaining cap 1002B. The reaction face 1620 can support the bearing1005 (see, for example, FIG. 10B). In some embodiments, the shift rodsleeve 1002A can include a surface 1720 and a shoulder 1721 adapted toreceive, for example, the inner bore 1830 of a shift nut 1006. The shiftnut 1006 can be secured to the shift rod sleeve 1002A by a snap ring1007 (see, for example, FIG. 10A) received in a groove 1722. In oneembodiment, the retaining cap 1002B can be a generally cylindrical diskwith a central bore 1614. Threads 1610 can be provided on the outercircumference of the cylindrical disk to mate with the cup end 1702. Theretaining cap 1002B can further include a number of counter bores 1612,which are adapted to receive a tool, for example pliers, for fasteningthe cap to the shift rod sleeve 1002A.

Referring now to FIG. 18, in one embodiment the shift nut 1006 can be agenerally rectangular body with a central bore 1830 adapted to matewith, for example, the surface 1720 and the shoulder 1721 of the shiftrod sleeve 1002A. Shoulders 1832 and 1833 are configured to adapt to theidler assembly 504; hence, during operation, in one embodiment the shiftnut 1006 rotates and translates with the idler assembly 504. The shiftnut 1006 couples to the shift rod sleeve 1002A.

During operation of the IVT 100, a zero output speed condition orpowered zero condition may be desired. The command for a zero outputspeed can be transmitted to the IVT 100 by the control linkage 310 (see,for example, FIG. 3). In one embodiment of the variator 200, the zerooutput speed condition generally corresponds to an arrangement whereinthe axis of rotation of the power rollers of the power roller assembly502 has a tilt angle substantially equal to zero relative to thelongitudinal axis of the variator 200. The tilt angle of the powerroller assembly 502 generally corresponds to an axial translation of theidler assembly 504. Consequently, the zero output speed conditioncorresponds to a particular axial position of the idler assembly 504.Typically, the engagement surfaces 1512 of the output feedback rod 1001Balign with the engagement pins 1010 during the zero output speedcondition. The engagement pins 1010 couple the shift rod assembly 1001to the output member 528, consequently a change in output speed can becommunicated to the ratio adjuster 240. The coupling of the threads 1108to the threads 1414 result in the conversion of the rotational inputfrom the output member 528 into an axial translation of the shift rodassembly 1001. The shift rod assembly 1001 can have a minimal degree ofallowable rotational and axial travel with respect to the controlinterface mechanism housing 1100. The amount of allowable rotational andaxial travel can be adjusted with the adjustment members 1020 and 1021.The adjustment members 1020 and 1021 define the allowable axial travelof shift rod assembly 1001 with respect to the control interfacemechanism housing 1100. The axial translation of the shift rod assembly1001 axially translates the idler assembly 504 thereby tilting the powerroller assemblies 502 to achieve an adjustment of speed ratio of thevariator 200, for instance to bring the output speed to zero.Preferably, during the zero output speed condition, the controlinterface mechanism housing 1100 is substantially stationary and theaxial movement of the shift rod assembly 1001 is substantiallyundetectable to the user of the IVT 100. For example, a user would notnotice the IVT 100 shifting to maintain the zero output speed condition.The length of the engagement surfaces 1512 defines the ratio rangearound a zero speed for which the engagement pins 1010 affect the speedratio of the variator 200. When the user shifts the shift rod assembly1001 substantially away from a zero speed ratio such that the engagementsurfaces 1512 are not aligned with the engagement pins 1010, theengagement pins do not contact the output feedback rod 1001B.

Turning now to FIGS. 19A-19B and referring again to FIG. 5, in oneembodiment a carrier clamp 514 includes a generally cylindrical bodywith a central bore. A number of holes 1912 can be provided to, amongother things, facilitate the delivery of lubricant, such as transmissionfluid, to the central axis of the variator 200. The carrier clamp 514includes a threaded portion 1910 formed on the central bore to couplethe carrier clamp 514 to the main shaft 510. Among other things, thecarrier clamp 514 operationally couples the main shaft 510 to thecarrier 512. The central bore can be further provided with a groove 915,which can be adapted to receive, for example, an o-ring. In oneembodiment, the carrier clamp 514 includes a reaction surface 1916 onone end. The reaction surface 1916 is configured to couple to thecarrier 512. A shoulder 1932 and a reaction surface 1930 can be providedto support the bearing 515A that axially supports the carrier 512. Thecarrier clamp 514 can include a groove 1934 for receiving a snap ringthat aids in retaining the bearing 515A. A number of flats 1920 can beformed on the outer circumference of the carrier clamp 514. The flats1920 can facilitate the mounting of the carrier clamp 514 onto the mainshaft 510.

Passing now to FIGS. 20A-20E and still referencing FIG. 5, in oneembodiment the main shaft 510 can be a generally cylindrical body havinga first central bore 2010 and a second central bore 2012. In someembodiments, the central bores 2010 and 2012 are adapted to receive anumber of support bearings, such as bearings 540 and 542, which areconfigured to support certain components of the ratio adjuster 240. Themain shaft 510 can include a number of slots 2014 that are adapted toreceive the shift nut 1006 (see, for example, FIG. 3). In oneembodiment, the slots 2014 provide axial clearance for the shift nut1006. The main shaft 510 can include a slot 2016 having a crescent shapeto receive, for example, a key that can couple the input pulley 106 tothe main shaft 510. A number of lubrication holes 2020 can be formed onone end of the main shaft 510. In this embodiment, two lubrication holes2020 are provided on the main shaft 510 and are configured to align withthe lubrication holes 1912 on the carrier clamp 514. A seal groove 2030can be provided on one end of the main shaft 510. In one embodiment, themain shaft 510 includes a bearing support shoulder 2032 that can belocated in the first central bore 2010. The bearing support shoulder2032 can be configured to couple to the bearing 542, for example. Duringoperation, lubricant can be directed along the inner bore of the mainshaft 510. The seal groove 2030 can retain a shaft seal, for example, toprevent leakage of lubricant from the inner bore of the main shaft 510.

Referring specifically to FIGS. 20D and 20E, in one embodiment the mainshaft 510 includes a number of knurls 2040A and 2040B. The knurls 2040Aand 2040B can be configured to facilitate the rigid coupling of the mainshaft 510 to the carrier 512. One end of the main shaft 510 can includea set of threads 2042 to engage the carrier clamp 514. A snap ringgroove 2041 can be formed on the other end of the main shaft 510. Thegroove 2041 is configured to receive a snap ring for axially securingthe carrier 512. A bearing surface 2044 can be provided on the mainshaft 510 for supporting the bearing 515B. Snap ring grooves 2043 and2046 receive, for example, snap rings that can axially retain thesupport bearing 515B.

Passing now to FIG. 21, in one embodiment the housing assembly 102includes an upper housing member 102A, an intermediate plate 102C, and alower housing member 102B. The upper housing member 102A can include anumber of holes 2132 for receiving fasteners such as bolts. Likewise, anumber of holes 2122 and 2112 can be provided on the intermediate plate102C and the lower housing member 102B, respectively. The holes 2132,2122, and 2112 can be arranged on flange surfaces 2130, 2120, and 2110,respectively. The flange surfaces 2130, 2120, and 2110 can generallyextend around the perimeter of the respective housing assembly members102B, 102C, and 102A, and provide a base for, among other things,sealing the IVT 100. A groove 2124 can be provided on the intermediateplate 102C to receive an o-ring (not shown). A bracket 2126 can furtherbe provided on the intermediate plate 102C. The bracket 2126 isconfigured to support the pivot lever 316. The cooling fins 110A can beformed on the external surface of the housing member 102A. Likewise, thecooling fins 110B can be formed on the external surface of the housingmember 102B. A number of internal cooling fins 110C can further beprovided on the interior surface of the lower housing member 102B.

Turning now to FIGS. 22A-22C, in one embodiment the lower housing member102B can include a support hub 2210. The support hub 2210 can be formedon the interior surface of the lower housing member 102B. The supporthub 2210 is adapted to cooperate with the output shaft 210 and theneutral throw-out bearing housing 226. A seal surface 2220 can beprovided to receive, for example, a shaft seal. A shoulder 2222 can beprovided that supports the bearing 211. Likewise, a shoulder 2224 can beprovided to support the bearing 212. A number of grooves 2226 can beformed on the support hub 2210 to retain the dowels 612 of the throw-outbearing housing 226. A clearance bore 2202 can be provided on the lowerhousing member 102B. The output shaft 210 extends from the IVT 100 atthe clearance bore 2202. A drain hole 2204 allows for removal oflubricant from the housing assembly 102. A number of through bores 2206can be provided on the lower housing member 102B and can be adapted tomount the IVT 100 to a vehicle structure.

Referring now to FIGS. 23A and 23B, in one embodiment the upper housingmember 102A can include a number of dowel bores 2302 arranged on theinternal cavity of the housing member 102A. The dowel bores 2302 can beconfigured to couple to certain components of the variator 200. Inparticular, the dowel bores 2302 can receive dowels that couple to theaxial force generator assembly 518. A shoulder 2304 can support a snapring, for example, that retains the bearing 515A. The cooling fins 110Acan be formed on the exterior of the housing member 102A, while thecooling fins 110D can be formed on the interior of the housing member102A. A through bore 2306 and a number of guide bores 2308 can beprovided to cooperate with and/or receive the manual neutral knobassembly 108. A lubricant port 2310 can be formed on the exterior of theupper housing member 102A and is configured to receive a hydraulicfitting to supply lubricant to the IVT 100. A piloting shoulder 2312 anda number of threaded bores 2314 can be provided to receive the housingcap 410 (see, for example, FIG. 4).

The foregoing description details certain embodiments of the invention.It will be appreciated, however, that no matter how detailed theforegoing appears in text, the invention can be practiced in many ways.As is also stated above, it should be noted that the use of particularterminology when describing certain features or aspects of the inventionshould not be taken to imply that the terminology is being re-definedherein to be restricted to including any specific characteristics of thefeatures or aspects of the invention with which that terminology isassociated.

What is claimed is:
 1. A method of controlling an infinitely variable transmission (IVT) coupled to an output shaft, comprising: receiving, from a command system, an indication of a desired transmission output speed of the IVT, wherein the desired transmission output speed is a zero output speed; sensing an output speed; and actuating a ratio adjuster to change a transmission ratio to adjust a non zero output speed to the zero output speed.
 2. The method of claim 1, wherein the IVT comprises a control interface mechanism coupled to the ratio adjuster and a control linkage.
 3. The method of claim 1, wherein the command system comprises an automated command system coupled to the control linkage.
 4. The method of claim 1, further comprising a user control interface coupled to the control linkage, wherein receiving an indication of a desired transmission output speed comprises receiving an input from a user.
 5. The method of claim 4, wherein the command system comprises an automated command system.
 6. The method of claim 1, wherein sensing the output speed comprises using a mechanical coupling.
 7. The method of claim 6, wherein the mechanical coupling comprises the ratio adjuster comprising an output feedback rod coupled to a shift rod driver.
 8. The method of claim 7, wherein sensing an output speed comprises sensing a position of the ratio adjuster of the IVT. 